The expression "off your guard" means that you are not prepared; that you are not watching for something and are not ready; that you are relaxed and not tense with waiting for some event.
it's like when you didn't expect something to happen . you didn't see that thing coming , so you're totally surprised and clueless !!
"Write it off" means to dismiss something.
To laugh allot
The meaning of the idiom "to slap the back off you" is fairly straightforward. It implies an exaggeration, that one would slap someone else so hard that their back would come off.
Can you figure out the meaning by defining the terms literally? No, so it is an idiom. Literally, it means to remove something, but figuratively it means for an airplane to get off the ground.
Showing off, being well dressed and flashy.
To lose ones temper and react violently.
Old sailing slang meaning to be no longer in danger.
It means being ticked off, or very mad.
Nothing. To get off the hook, however, means to escape punishment.
"To be" is not an idiom - it's a verb.
That usually pertains to a weapon discharging when you don't want it to.